Blowout preventer



1-1. ALLEN ETA!- BLOWOUT PREVENTER Filed March 1, 1954 7 Sheets-Sheet 1Madden 7: Works 1/0/7/7/F5- 0// ver Herb er f A/len JNVENTORS H. ALLENETAL 2,912,214 BLOWOUT PREVENTER 7 Sheets-Sheet 2 ww he Mao o'er? 7.'Work: d0/7/7 0// Ver Herber/ A//@/? v J'NVE/VTORJ ATTORMSKS Nov. 10,1959 Filed March 1, 1954 Nov. 10, 1959 H. ALLEN ETAL BLOWOUT PREVENTERFild March 1, 1954 7 Sheets-Sheet 5 Mada en 7: Works 1/0/2/7 P 0// verINVENTORS I Herbert A//e/7 ATTORNEYS Nov. 10, 1959 H. ALLEN ETAL2,912,214

' BLOWOUT PREVENTER Filed March 1, 1954 '1 sheets-sheet 5 Madden 71War/(J 4/0/10 P.- O/lver Herb er f ,4 //en INVENTORS Nov. 10, 1959 H.ALLEN ETAL 2,912,214

BLOWOUT PREVENTER 7 Filed March 1, 1954 7 Sheets-Sheet 6 Mada en 7.'Works i/o/zfl F 0// var fierber 2 A //e/7 INVENTORS wiw ir ATTOR/VE VJNov. 10, 1959 H. ALLEN ETAL 2,912,214

BLOWOUT PREVENTER Filed March 1, 1954 v I 7 Sheets-Sheet 7 Madden 71War/k: /0/7/7 R 0// ve/' f 7/ [Z Herbe I/N4VEN?0/1ZS BW M/fi ATTORNEYSBLOWOUT PREVENTER Herbert Allen, Madden T. Works, and John P. Oliver,Houston, Tex., assignors to Cameron Iron Works, Inc, Houston, Tex., acorporation of Texas Application March '1, 1954, Serial No. 413,114

20 Claims. (Cl. 251--1) This invention relates to a blowout preventerwhich is primarily intended to be secured to the upper end of a wellcasing to provide for sealing or closing olf the annular space betweenthe well casing, or one of the larger pipes in a well, and the welltubing or one of the other smaller pipes in a well. When no smaller pipeis in the well extending through the blowout preventer, it is providedwith so-called blank rams for closing off the opening through theblowout preventer through which the pipe might pass and, hence, closingoff the opening through the well pipe on which the blowout. preventer ismounted.

The major use of blowout preventers is during the drilling of a well bythe rotary drilling method, during which the rotary drill pipe extendsinto the Well through the open blowout preventer. The preventer is thusready so that it may be closed about the drill pipe at any time when ablowout is threatened, thereby shutting off the annular space about thedrill pipe, or, if no drill pipe is in the well, the preventer may beoperated to close off the entire upper end of the well. The blowoutpreventer to which this invention relates is of the type having opposedrams which may be moved toward or away from the pipe opening through thepreventer for the purpose of closing ofl or leaving clear the pipeopening through the preventer.

It is the general object of this invention to provide such a preventerwhich is lighter, more compact and safer, and on which it is easier andfaster to change ram parts than on previous structures.

Blowout preventers of the type referred to have been used extensively inconnection with deep wells for many years and improvements havebeen madetherein heretofore which have brought them to a high degree ofperfection. An example of one of the more modern and popular forms ofblowout preventers of this type which has enjoyed extensive commercialsuccess is that illustrated in Letters Patent United States No.2,387,106, issued October 16, 1945.

However, blowout preventers heretofore employed have been somewhat largeand bulky and have required considerable vertical space because of theirheight, and it has been found desirable to decrease the amount ofvertical space required for a blowout preventer as well as to reduce theoverall size of the preventer and its weight, without reducing itseifectiveness and the efficiency of its operation. In the past, also,blowout preventers have been operated by fluid under pressure fromsuitable sources, but the provisions for supplying such fluid to theappropriate points in the blowout structure have entailed in mostinstances considerable piping and duct work in the space surrounding themain body of the blowout preventer. Also, other parts of the preventersemployed in the past have protruded from various parts of the preventerand, with such pipes and duct work, have been exposed to possible damagefrom being knocked off in the moving of heavy equipment and the like.

2,912,214 Patented Nov. 10, 1959 It is an object of this invention toprovide a blowout preventer which will be more compact in every respectthan those heretofore employed for accomplishing substantially the samework.

It is a further object of this invention to provide such a blowoutpreventer in which there will be'no projecting parts or duct worx whichare apt to be damaged by movement of heavy equipment in the spacesurrounding the blowout preventer.

Still another object is to provide a blowout preventer in which thecontrolling mechanisms are considerably simplified as compared to thoseheretofore employed.

Another object of this invention is to provide a. blowout preventer anda ram construction therefor in which the changing of ram equipment forthe purpose of enabling the preventer to accommodate different sizes ofpipe, to replace worn parts, or to substitute ram portions capable ofclosing the entire opening through the preventer for those capable ofclosing the annular space about a pipe, may be more readily and simplyaccomplished.

In order to facilitate this description and the definitions of theinvention in the appended claims, the terms forward or front will beused to designate those portions of the rams and guideways nearest thepipe opening of the preventer and rearward or rear to designate thoseportions more remote from that opening. Upper, lower, horizontal,vertica, etc., will be used to refer to parts so disposed or locatedwhen the preventer is in actual use on a well.

The foregoing and other objects of the invention are accomplished ingeneral by the expedients of placing the operating and ram changingpiston and cylinder arrangements in side by side relationship insubstantially hori zontal position, providing a pair of smaller diameterram operating pistons instead of one larger piston, employing rams ofoval cross section with the major axis of the oval horizontally disposedand embodying the entire arrangement in a unitary compact body and headassembly. In such an assembly, the passageways for supplying power fluidto the various piston and cylinder combinations are formed in the headand in the body of the preventer so as not to leave projecting parts andduct work which may readily be damaged by exterior movement of heavyequipment. In this connection, the ram locking screw customarilyemployed in connection with blowout preventers of the ram type forholding the rams in closed position is in this structure mounted betweenJ the two ram cylinders and is in use protected by said two cylindersagainst possible damage by external movement of heavy equipment.

Furthermore, the entire arrangement has been devised in such fashionthat the same controls for applying power fluid for advancing andretracting the ram in ordinary use of the preventer may be employedalso, in the same manner and without extra conduits, for moving the headstructure away from the body of the preventer for the purpose ofchanging the packing assemblies and the like of the rams. Thus, themovement of the same control which retracts the rams toward the head isalso operative to admit fluid under pressure for the purpose ofretracting the head carrying the ram away from the body of the preventerso that the parts of the ram necessary to be removed and changed may beaccessible.

In the accompanying drawings and'following description, there is setforth one preferred embodiment of this invention by way of illustrationand example. In these drawings, in which like numerals designatecorresponding parts throughout:

Fig. 1 is a perspective view of an assembled blowout preventerconstructed in accordance with this invention,

a with flow connections for supplying power fiuid to the preventer beingshown diagrammatically.

Fig. 2 is a partially diagrammatic illustration of the flow passagewaysand piston and cylinder combinations embodied in the working parts ofthe blowout preventer shown in Fig. 1, the parts being illustrated inthis figure in the position they would occupy with the preventer in useand the preventer rams closed about a pipe passing therethrough.

Fig. 3 is a view similar to the right hand portion of Fig. 2 but showingthe ram retracted so as to leave open the annular space about a pipepassing through the preventer.

Fig. 4 is a view similar to Fig. 3 but showing the head structurecarrying the piston and cylinder combinations and the ram moved awayfrom the body of the preventer for the purpose of changing ram parts.

Fig. 5 is a view of the preventer partly in plan and partly inhorizontal cross section through the pistons, cylinders and ram guidewayof one end of the preventer.

Fig. 6 is a view of the preventer partly in side elevation and partly invertical cross section through the preventer illustrated in Fig. 1,showing more in detail the structure of the rams and of the ram lockingscrews.

Fig. 7 is an exploded view in perspective illustrating the blowoutpreventer shown in Fig. l and depicting the relation of the parts toeach other as they are assembled.

Fig. 8 is a perspective view of a blowout preventer ram with its ramoperating pistons and ram locking screw, constructed in accordance withthis invention.

Fig. 9 is a fragmentary view showing a vertical longitudinal crosssection through one of the upper ram guideways, illustrating the mannerof removal of the ram packer assembly and the pipe centering guide fromthe preventer.

Fig. 10 is a vertical cross section through the ram transverse to itsdirection of forward and rearward movement.

Fig. 11 is an exploded perspective view of the ram packer assembly,taken from above to show the upper surfaces of the parts.

Fig. 12 is a similar view of the same assembly but taken from below toshow the lower surfaces of the parts.

Referring now more particularly to the drawings, it will be seen thatthe blowout preventer illustrated is actually in effect two blowoutpreventers, one above the other. It is customary in practice to placeone preventer above the other and connect them together, but, in thisinstance, in order to provide a more compact structure and one whichwould not require so much head room under the derricks during drillingoperations, two such units have been formed into a single bodystructure. The lower such unit is illustrated at 10 in Fig. 1 and theupper such unit at 12. stood that these two units are identical instructure except that in practice the lower one is customarily, thoughnot necessarily, provided with blank rams or rams capable of closing offthe entire space within the pipe Opening through the preventer when nopipe is in place therein, while the upper preventer unit at 12 iscustomarily provided with rams capable of embracing a pipe when oneextends through the preventer and closing 01f the annular space aboutthe pipe. For the purpose of this description, reference will be madehereafter to only one of these units.

Through the body of this blowout preventer from top to bottom is anopening through which a pipe may be passed, which opening will bereferred to in this application as a pipe opening 18. The body aroundthe lower end of this opening is adapted to be secured to a casing heador the like, the same being secured thereto by means of studs engaged inthe tapped openings 13 in Fig. 6. Likewise, at the upper end of thisopening such other equipment as desired may be secured by means It willbe underof studs engaged in the tapped openings 14. Conventional sealrings will be employed in grooves 15 and 16 in the lower and upper facesadjacent the tapped openings 13 and 14 in a manner well known. The pipeopening referred to which passes vertically through the preventer bodyis illustrated at 18. It is also customary to provide a side outlet 20with suitable means for connecting a pipe thereto, this outletcommunicating with the pipe opening 18 at a point below the lower ramsof the lower unit.

Intersecting and extending laterally in opposite directions from thepipe opening 18 are ram guideways 22, in which the rams, which mayeither be blind rams generally designated at 24 in Fig. 6 or pipeembracing rams generally designated at 26 in Fig. 6, may be employed.These rams will be described more in detail hereafter, but are adaptedto be moved forward and rearward toward and away from a position inwhich they will interrupt the pipe opening through the preventer bodyand thereby shut off flow either through the pipe opening without anypipe therein as by means of the blind rams 24, or shut off flow throughthe annular space around the pipe therein as by means of the pipe rams26.

The rams are normally moved forward and rearward by means of ram pistons28 operating in ram cylinders formed in a head structure which in normaloperation of the blowout preventer is rigidly secured and sealed to theblowout preventer body transversely of the outer ends of the ramguideways.

Ram pistons 28 are carried on the ends of rods 29, being rigidly joinedthereto, and these rods are in turn threaded or otherwise rigidly joinedto the ram carrier 30 which forms the major portion of the ram body.

The head structure referred to consists of a bonnet 32 and anintermediate flange 34. The bonnet 32 has formed therein the ramcylinders 36 which receive and cooperate with the ram pistons 28, andthe open ends of these cylinders 36 are closed about the rods 29 by theintermediate flange 34 which is secured to the bonnet 32 by suitablemeans such as cap screws 38. In the openings through the intermediateflange 34 surrounding the rods 29 are suitable packing so that the ramcylinders 36 are closed at their rod ends about the rods 29 as well asat their opposite or head ends. Thus, there is provided a double actingpiston and cylinder combination whereby the rams 26 may be moved bothforwardly and rearwardly depending upon the direction of application ofpressure to the pistons 28.

It is to be noted that the rams 26 and their guideways 22 are made ovalin cross section with their major axes disposed horizontally, whichmakes it possible to make a blowout preventer with a much shortervertical dimension than with round rams, yet have the advantages whichresult from the elimination of flat bearing surfaces and corners orcrevices on and in which sand, shale and other material may accumulateand interfere with the operation of the rams or cause excessive wear.Carrying this idea further, the power for the ram actuation is providedthrough two pistons and cylinders as above mentioned instead of one, andthese are spaced apart and lie in substantially the same horizontalplane which is substantially the same as the plane of the major axis ofthe oval ram.

The composite head structure provided by the bonnet 32 and intermediateflange 34 secured together by the cap screws 38 as above described, isin normal operations of the preventer secured to the body in a positiontransversely of the ram guides 22 and across their outer ends by meansof capstan screws 42 of which four are illustrated for each head. itwill be seen that when the head structure is thus rigidly held withrespect to the body of the preventer, the application of fluid underpressure alternately to the head ends and to the rod ends of thecylinders 36 will result in forward and rearward motion of the rams 26in their respective guideways 22. At this point it may be noted alsothat intermediate the rods 29 each of the ram carriers 30 is providedwith a boss 44 which is internally tapped and threaded to receive alocking screw 45, the inner end of which is threaded at 46 to engage thetapped opening in the boss 44 and the outer end of which is in the formof a smooth stem with a non-circular configuration on its outer end sothat it may be engaged by a wrench and rotated. Intermediate thethreaded portion and the smooth portion this screw is provided with alaterally extending flange 47. The bonnet 32, intermediate the portionsin which the cylinders 36 are formed, is provided with a recess and thesmooth portion of the screw just'described extends through an opening inthe bonnet and into such recess so that although it is accessible fromthe exterior of the bonnet it is protected by the portion of the bonnetin which the cylinders 36 are formed. The action of this screw will bereadily understood in that when the screw is in the position illustratedin Fig. 6, it may move forward and rearward with the ram 26 and will notinterfere with such movement, but it may be used to manually close ram26 or with the ram 26 in its closed or forward position the screw may berotated by means of the noncircular portion until it is backed out ofthe boss on the ram carrier to engage the flange 47 with the innersurface of the bonnet. In this position the ram 26 will be locked closedand cannot be retracted.

While the head structure comprising the bonnet and the intermediateflange secured together is, during normal operation of the preventer,rigidly secured and sealed to the body by the capstan screws 42, thishead structure is also mounted on the body with a telescoping connectionwhich, when the capstan screws 42 are released, permits movement of thishead structure away from the body of the preventer by a distance whichis not substantially less than the forward and rearward dimension of theram 26.

The telescoping connection just referred to is comprised of a pair ofwhat may be termed head pistons 50 and 52 slidably carried in andforming a sliding seal within head cylinders 54 and 56 formed within thebonnet 32 with axes substantially in the same plane with the axes ofcylinders 36 and on opposite sides thereof. These pistons 50 and 52 arecarried on piston rods 58 and 60, respectively, both of which are hollowand both of which extend through the intermediate flange 34 and arethreadedly or otherwise rigidly secured to the body. The rod ends of thecylinders 54 and 56 are closed about the rods 58 and 60, respectively,by means of suitable packing 61 within the intermediate flange 34,thereby making the piston and cylinder combinations formed by headpistons 50 and 52 and the head cylinders 54 and 56 double acting. Itwill be seen that if fluid under pressure is admitted to the rod ends ofthese cylinders 54 and 56 it will tend to move the head structure intotight engagement with the body in which position it is shown, forexample, in Fig. 5, but that if fluid under pressure be introduced intothese cylinders in their head ends, such pressure will tend to move thehead structure away from the body, and with the capstan screws 42released, will move the head structure away from the body until suchmovement is stopped as by contact of the head pistons 50 and 52 with theclosures of the head cylinders which are carried by the intermediateflange 34. Such retractive position is illustrated in Fig. 9 and also inFig. 4 and it will be appreciated on reference to these two figures thatwhen the parts are in this position it is possible to remove by liftingupwardly the wearing and size determining parts of the ram, an operationwhich will be described more in detail in the later part of thisspecification.

combinations in order to actuate them as desired, this is shown insofaras the flow passages in the body and head structure are concerned inFigs. 2, 3 and 4. It will be appreciated that in these figures thepassageways are shown for the purpose of convenience as lying all in oneplane but that in actuality, while the passages shown as being withinthe head structures are actually within the head structures and thoseshown as being within the body are actually within the body, they do notnecessarily lie in the planes where they are shown but are located inthe head and body structures in positions most convenient from thestandpoint of design but having no bearing on the patentability thereof.

First of all it is noted that the body has two operating fiuidpassageways 62 and 64, each of which has an open ing as indicated at 65and 66, respectively, so that it may be connected to an external conduitfor supplying fluid under pressure thereto or for receiving fluidtherefrom.

Next it is noted that the conduit 62 in. the body is in communicationwith the passageway 67 through the hollow rod 58 and that this pasageway67 leads through the head piston 50 and opens into the head end of thehead cylinder 54. Leading from the head end of the cylinder 54 there isa passageway 68 leading through the bonnet and intermediate flange andcommunicating through branch lines 69 and 70 with the rod ends of ramcylinders 36, and also having communication to an extension 71 withthe'head end of head cylinder 56. In this respect the opposite ends ofeach blowout preventer section are identical and itwill be seen fromthis description that upon the application of pressure fluid through theopening 65 such pressure will be applied to the head ends of the headcylinders 54 and 56 and will tend to move the head structure away fromthe body, and such pressure will be simultaneously applied to the rodends of the ram cylinders 36 which will cause movement of the ram 26 ina rearward direction until it engages the intermediate flange 34 as anabutment. It will be appreciated that in normal operation of thepreventer, during which the head structure is secured to the body bymeans of capstan screws 42, the pressure in the head ends of headcylinders 54 and 56 will be ineifective tomove the head stnucture withrespect to the body but that such pressure in ram cylinders 36 willretract the ram 26 to the position illustrated in Figs. 3 and 5, unless,of course, the ram is locked in its forward position by the screw 45, inwhich event there will be no movement whatever resulting from theapplication of pressure as described.

If, on the other hand, the capstan screws be released, then uponapplication of pressure in the manner just referred to, the ram will beretracted into engagement with the intermediate flange as abovedescribed, and in addition thereto the head structure will be moved awayfrom the body until it occupies the position illustrated in Figs. 4 and9, in which position portions of the ram may be removed as hereinafterdescribed.

Referring to the passageway 64 in the body, it is noted that thispassageway is in communication with the hollow interior 74 of the rod60. This hollow interior 74, however, does not open through the headpiston 52 as does the hollow interior 67 through the head piston 50. Onthe contrary, the head piston 52 is imperforate and small passageways 75are provided between the interior 74 of the rod and the interior of therod end of the head cylinder 56 so that pressure from opening 66 whenapplied thereto will be communicated to the rod end of the head cylinder56. This rod end of head cylinder 56 is connected through passageway 76and branches 77 and 78 with the head ends of the ram cylinders 36, andthrough an extension of the passageway 76, indicated at 79, the same isconnected to the rod end of head cylinder 54.

Thus, it will be seen that when fluid under pressure is applied throughthe opening 66, this fluid under pressure will tend to act on the rodends of the head cylinders 54 and 56 to move the head structure intotight engagement with the body, and to act on the head ends of the ramcylinders 36 to move the ram 26 forwardly to closed position. Duringnormal operation of the preventer with the head structure secured by thecapstan screws 42 to the body, the only action resulting from theapplication of pressure fluid through the opening 66 will be to move theram 26 forwardly to its closed position, but if perchance the capstanscrews had previously been released and the head structure moved topositions spaced from the body as illustrated in Figs. 4 and 9, then thethe application of the pressure through openings 66 would serve both toclose the head structure against the body so that the capstan screwsmight be replaced to hold it in such position, and to advance the ram toclosed position.

On reference to Fig. 1 the exterior connections for supplying fluidunder pressure to operate the preventer are illustrateddiagrammatically. From this figure it will be seen that only twoexterior lines or conduits which are indicated by the numerals 30 and 81connect respectively to the openings and 66 and are all the connectionswhich need be made to the preventer for operating the upper unitthereof. These lines are connected to a control valve 82 which controlsthe entire operation of the upper unit by movement selectively to eitherof two positions. In one of these positions it serves to connect theconduit to the pump 88 which draws fluid from the reservoir and forcesit under pressure through the valve 82 and the line 30 into the opening65 with the results heretofore described, while the line 81 is connectedthrough the valve 32 to the discharge line 89 which empties into thereservoir 91? and permits the return of spent fluid from the respectivecylinders. In the other position of valve 82 it connects conduit 81 topump 38 to supply power fluid under pressure to opening 66 with theresults heretofore described, while line 80 is connected to dischargeline 39 to permit return of spent fluid from the cylinder ends incommunication with opening 65.

The operation of the lower unit likewise is controlled through twoconduits 84 and 85 and a valve 86 which serves to connect themalternatively to the pump 88 and to the discharge line 89, respectively.

Reference will now be had more in detail to the structure of the ramswhich is highly advantageous particularly in connection with the blowoutpreventer construction which has been described.

As above mentioned, each of the rams has a body which is oval in crosssection in a direction transverse to its direction of forward andrearward movement so that it will take up as little vertical space aspossible but yet so that it will have the advantage of providing no flatsurfaces and corners that would tend to accumulate grit and the like.This body is provided in major portion by a ram carrier 3% to which theram operating rods 29 are rigidly connected as heretofore described.This ram carrier is not intended to be removed under any ordinarycircumstances and its removal is unnecessary for the purpose of eitherchanging the ram packing assembly from one size to another Or to providea blank for closing off the entire pipe opening, or for the purpose ofchanging the pipe centering guide to accommodate a different size ofpipe. As illustrated in Figs. 7, 8, 9 and 10 the upper forward portionof this carrier is cut away to provide for the reception of the pipecentering guide and of the ram packer assembly which, together with thecarrier, make up the complete ram. The carrier has a forwardly extendingledge 92 on which the pipe centering guide 93 is adapted to rest. Thisguide is in the form of an arc, the interior curvature of which is of asize to fit the pipe with which the ram is to be used and the outercurvature of which is of a size to fit within the recess provided forthe guide in the ram carrier. On the forward ends of the guide 93 areprojections which actually provide the pipe centering guides, that onone end being adjacent the upper surface of the guide member as shown at94 and that on the other end being adjacent the lower surface of theguide member as shown at 95. These project in advance of the forwardface of the ram and are adapted to match with corresponding recesses onan identical pipe centering guide on the opposed ram so that when bothrams are closed these projections will overlie and underlie each other.The pipe centering guide is not secured to the carrier by means of boltsor other holdfast means but is provided with interlocking means in theform of dowels 96 which engage within dowel openings 97 formed in thecarrier so that as long as the pipe guide is held downwardly against theledge 92 on the carrier it will be prevented from movement with respectto the carrier.

The ram packer is embodied in an assembly which comprises a packerproper 98 and lower and upper ram segments 9'9 and ltlt), which are ofrigid material, such as steel, as contrasted with the flexible,resilient material such as synthetic rubber of which the packer properis mainly constructed. The packer is preferably of molded constructionin the form of an endless strip which is so disposed as to form asealing strip 101 across the forward face of the ram, a rearwardlyextending portion on each end of the forward sealing strip 101 asindicated at 102, and a part which curves upwardly and rearwardly acrossthe top of the ram to provide a sealing strip across the top of the ramas indicated at 103. This is preferably molded in one piece and forms anendless strip of sealing material. Completing the packer proper arepressure plates 104 and 105 countersunk in the upper and lower surfaces,respectively, of that portion 101 of the resilient packer which extendsacross the front face of the ram. These pressure plates terminate shortof the rear surface of this portion of the packer member and their rearsurfaces bear against the resilient packer material so that when theyare forced rearwardly they tend to force the material of the packing toflow out between them.

The upper and forward portion of each ram is provided by the uppersegment 1% whereas the base of each packing assembly is provided by thelower segment 99. These two segments are so formed that they extend intothe opening provided by the endless packer element and completely fillthis opening as well as confine the forward strip portion 161 of thepacking element on both its upper and lower surfaces and provide asupport for the rear portion of this forward strip. The upper segment 1%likewise provides a limiting wall for the forward surface of the curvedstrip 1% of packing material which extends up and across the top of theram, and the lower segment extends underneath this strip 193 to providea limiting wall for its unclersurface. The upper and lower segments,after being assembled with respect to each other and with respect to thepacking element in the manner indicated, are secured together by meansof cap screws 1%, the heads of which are countersunk into the outersurface of the upper segment and threaded into suitable tapped openingsin the lower segment. It is to be noted that these cap screws servemerely to secure these segments together and not to secure them to theremainder of the ram.

In this latter connection, it will be seen that the ram carrier isprovided with an upstanding substantially semicircular ridge or flange107 which projects just above the upper surface of the pipe centeringguide when it is in place in the ram carrier, and which provides asemicircular recess behind this flange iii 7. The lower segment 99 isprovided with a complementary formation which includes a downwardlyextending flange like portion 198 adapted to fit the groove behind theflange 107 so that when the ram packer assembly as above described isput into position on the ram carrier, the ram packer assembly, like thepipe centering guide, will be free to move upwardly away from the ramcarrier but will be interlocked with portions of the ram carrier toprevent it from moving forwardly and rearwardly with respect to the ramcarrier. The ram carrier also has an upstanding 9 rear portion 109 whichforms a rear abutment for the packer assembly and particularly for thepacker element along the strip 103.

Thus, it will be seen that when this ram as described is in place withinits guideway in the body the pipe centering guide 93 will be held inplace by the ram packer assembly and the ram packer assembly in turnwill be held against movement upwardly and away from the carrier byengagement with the ram guideway so that the entire ram will operate asa unit. In this connection it is noted that the ram guideway is formedso that it closely embraces and fits the ram throughout the uppercircumferences and throughout the lengths of both of them, so that theram packer and pipe guide will be held in place on the carrierthroughout the travel of the ram in the guideway. On the other hand,when the ram is withdrawn from its guideway by the action of the rampistons 28 and the head pistons 50 and 52 with the capstan screwsdisconnected, the ram packer assembly first, and, when it is desired,also the pipe centering guide may be removed from the ram by simplylifting it upward. For this purpose and to make easier the removal ofthe ram packer assembly, the upper segment 100 is provided with a tappedopening 110 with which a lifting eye may be engaged.

The ram guideways also closely embrace the entire circumferences of therespective rams when rams are in their most rearward positions withinthe guideways, but forwardly of their rear ends the guideways have theirlower surfaces flared away from the rams in an inward and downwarddirection as shown at 111, thereby avoiding collection of sand or debrisbelow the rams and in cooperation with relief slots 112 in the ramcarrier, assuming that pressures on its forward and rear faces will besubstantially equal. The packer strip portion 101 and the partsextending therefrom rearwardly along the sides of the rams are locatedabove the major axis of the oval of the rams. This makes for betterbalance of pressures on front and rear surfaces of the rams when closed,in that the required opening force is only that of the well pressure onan area substantially equal to the area of the forward face of the ramabove the packer.

When employed as a ram within the ram guideway, this composite ram maybe advanced until it comes in contact with the pipe and/or theopposed'ram, at which point the packing material will be completelyconfined and additional movement of the ram will drive the pressureplates 104 and 105 into the confining space thereby displacing theconfined packing material and increasing pressure therein to cause it toseal at all contacting surfaces. These confining surfaces are providedby the segments 99 and 100, the rear portion 109 of the ram carrier, thepressure plates 104 and 105, the adjacent surrounding surface of theguideway, and the surface of the pipe or opposed ram against which theface 101 is abutted.

The operation of this device is believed to be clear from the foregoingbut may be briefly reviewed as follows:

The blowout preventer, mounted upon a well casing as previouslydescribed, may have a drill pipe or the like extending therethrough ormay have nothing extending through it. For this reason the rams of oneblowout preventer unit are customarily provided with forward facesadapted to engage the forward face of the opposed ram completely acrosssuch forward faces and thus to close off the pipe opening when no pipeis in place. This may be accomplished by operation of the valve 36 so asto connect to the pump 88 that one of the lines 84- or 85 which leads tothe passageway communicating with the head ends of the cylinders 36. Thecapstan screws 42 being secured to the body of this blowout preventerunit, the head pistons and cylinders will remain inactive while the rampistons will be caused to force the rams forwardly to closed position.During this movement flow from the other of the lines 84 or 85, as thecase may be, will takeplace as the pistons 28 move to reduce the size ofthe ram cylinders 36 on their rod ends.

The same operation will take place under the control of the valve 82employing the upper blowout preventer unit in the event a pipe is inplace in the blowout preventer.

If now it be desired to replace .a worn ram packer elementor toreplaceboth the ram packer and the pipe guide for the purpose ofchanging the ram to engagea different size of pipe, the capstan screws42 on the head structures of that preventerunit will be disengaged andthe valve 82 or 86 will be operated so as to turnpressure fluid into thehead ends of the head cylinders and the rod ends of the ram cylindersand so as to vent fluid from the opposite ends of said cylinders. Thiswill cause the retraction of the rams into engagement with theintermediate flanges and will cause the retraction of the head structureincluding the intermediate flanges, the bonnets and the rams in adirection away from the blowout preventer body until the upper surfaceof the ram is exposed upwardly. Thereupon, if only the ram packerassembly is to be changed, a lifting eye may be engaged with thethreaded opening 110 and the ram packer assembly lifted out as a unit.

The pipe centering guide then may or may not be removed and replaceddepending on what is desired. A new ram packer assembly may be then putin place and upon-operating the appropriate valve 82 or 86 to reversethe direction of application of fluid under pressure, the head structurewill be moved back into engagement with the body and the ram will bemoved to its most forward position overlying the pipe opening. Thecapstan screws '42 may then be replaced and the structure is ready foroperation.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings isto beinterpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

1. In a blowout preventer comprising a body having a pipe openingtherethrough and a ram guideway extending laterally from said pipeopening, a ram movable in said guideway to and from a positioninterrupting said pipe opening, the improvement which comprises a headdctachably secured to said body, a cylinder formed in the head, a pistonslidable within the cylinder and connected to the ram for moving saidram in its guideway in normal preventer operation, passageways in thehead connecting with the cylinder for supplying power fluid to oppositesides of the piston, and piston and cylinder means interconnecting saidhead and body for moving said head with respect to said body.

2,. A blowout preventer according to claim 1, in which said]first-mentioned cylinder and the cylinder of said piston and cylindermeans are disposed side by side with their axes substantially in a planetransverseto the axis of the pipe opening.

3. A blowout preventer according to claim 1, in which said piston andcylinder means includes another cylinder formed in the head, a pistonslidable in said other cylinder, and a rod connecting the last-mentionedpiston to the body, and said power fluid passageways connect with saidlast-mentioned cylinder in series with the first-mentioned cylinder.

4. A blowout preventer according toclaim 3, in which illl there arepower fluid passageways in the body and said piston of said piston andcylinder means is hollow for supplying power fluid from the passagewaysin the body to the passageways in the head.

5. In a blowout preventer, a body having a pipe opening therethrough anda ram guideway extending laterally from said pipe opening, a ram movablein said guideway to and from a position interrupting said pipe opening,a head removably secured to said body across the outer end of saidguideway and having a ram cylinder formed therein, and a ram piston insaid cylinder connected to said ram, said head having two power fluidpassageways therein open into the opposite ends respectively of said ramcylinder and each also open through the surface of said head toward theadjacent portion of said body, said body having two power fluidpassageways therein connected respectively to the last mentionedopenings of the passageways in said head when said head is mounted inoperative position on said body, and each of said passageways in thebody having another opening to the exterior of said body to receive andconnect to an external conduit, and piston and cylinder means connectingthe head and body for moving the head toward and away from the body.

6. In a blowout preventer, a body having a pipe opening therethrough anda pair of ram guideways extending laterally in opposite directions fromsaid pipe opening, a ram movable in each of said guideways to and from aposition interrupting said pipe opening, a head removably secured tosaid body across the outer end of each of said guideways, each headhaving a ram cylinder formed therein, a ram piston in each of saidcylinders and a rod connecting each ram piston to the corresponding ram,each of said heads having two power fluid passageways therein, saidpassageways in each head being open into the opposite ends respectivelyof the cylinder in the corresponding head and each also open through thesurface of such head toward the adjacent portion of the body, said bodyhaving two power fluid passageways therein, one such passageway in thebody being connected to the last mentioned openings of the passagewaysleading to the head end of the cylinder in each of said heads and theother of such passageways in the body being connected to the lastmentioned openings of the passageways leading to the rod end of thecylinder in each of said heads when the heads are mounted in operativeposition on said body, and each of said passageways in said body havinga third opening to the exterior of said body to receive and connect toan external conduit, and piston and cylinder means connecting the headand body for moving the head toward and away from the body.

7. A blowout preventer as claimed in claim 5, in which there is atelescoping connection between each of the passageways in said head andthe corresponding passageway in said body.

8. A blowout preventer as claimed in claim 5, in which said piston andcylinder means includes a telescoping connection between each of thepassageways in said head and the corresponding passageway in said bodyincluding another cylinder formed in said head in communication With thepassageway in said head, a piston slidable in said other cylinder, ahollow rod connecting said lastmentioned piston to said body and havingits interior in communication with the passageway in said body and withthe interior of said cylinder, and means forming a sliding seal aboutsaid piston rod within said head.

9. In a blowout preventer, a body having a pipe opening therethrough anda ram guideway extending laterally from said pipe opening, a ram movablein said guideway to and from a position interrupting said pipe opening,a head removably secured to said body across the outer end of saidguideway and having a ram cylinder and a pair of head cylinders formedtherein, a ram piston in said ram cylinder and a rod connecting saidpiston to said ram, said head having two power fluid passageways thereinopen into the opposite ends of said ram cylinder respectively, said bodyhaving two power fluid passageways therein each having an opening to theexterior of said body to receive and connect to an external conduit, apair of hollow piston rods on said body having their respectiveinteriors at one end in communication with the respective passageways insaid body and extending into one of said head cylinders, a sliding sealin said head about each red at the entrance to its head cylinder, and ahead piston on each rod in sliding sealing engagement with the interiorof its head cylinder, the interior of one of said rods being incommunication with the interior of its head cylinder on the rod side ofits head piston and the interior of the other of said rods being incommunication with the interior of its head cylinder through its headpiston to the head side thereof, and one of said passageways in the headbeing in communication with the rod ends of both head cylinders and theother of said passageways in the head being in communication with thehead ends of both head cylinders.

10. A blowout preventer as set forth in claim 9, in which the passagewayconnected to the head end of the ram cylinder is also connected to therod ends of said head cylinders and the other passageway connected tothe rod end of the ram cylinder is also connected to the head ends ofthe head cylinders.

11. In a blowout preventer, a body having a pipe opening therethroughand a ram guideway extending laterally from said pipe opening, a rammovable in said guideway to and from a position interrupting said pipeopening, a head removably secured to said body across the outer end ofsaid guideway and having a pair of spaced ram cylinders formed therein,the axes of said ram cylinders lying in a plane substantially normal tothe axis of said pipe opening, a ram piston in each ram cylinderconnected to said ram, said head having a recess in its external surfacebetween said cylinders, and a locking screw extending from said recessthrough said head to engage said ram for locking it in closed position,said screw lying partly in the recess between said cylinders.

12. In a blowout preventer, a body having a pipe opening therethroughand a ram guideway extending laterally from said pipe opening, a rammovable in said guideway to and from a position interrupting said pipeopening, a head removably secured to said body across the outer end ofsaid guideway and having a ram cylinder formed therein, a ram piston insaid cylinder connected to said ram, a head cylinder in said head, ahead piston in said head cylinder, a rod connecting said head piston tosaid body, each of said piston and cylinder combinations being doubleacting, means for supplying power fluid under pressure simultaneously tosaid ram cylinder in a direction to move said ram away from said headand to said head cylinder in a direction to move said head toward saidbody, other means for supplying power fluid under pressuresimultaneously to said ram cylinder in a direction to move said ramtoward said head, and to said head cylinder in a direction to move saidhead away from said body, and means for removably securing said head tosaid body.

13. In a blowout preventer, a body having a pipe opening therethroughand a ram guideway extending laterally from said pipe opening, a rammovable in said guideway to and from a position interrupting said pipeopening, a head removably secured to said body across the outer end ofsaid guideway and having a ram cylinder formed therein, a ram piston insaid ram cylinder connected to said ram, said head having also a pair ofhead cylinders in said head on either side of said ram cylinder, a headpiston in each of said head cylinders, a rod connecting each of saidhead pistons to said body, each of said piston and cylinder combinationsbeing double acting, means supplying power fluid under pressuresimultaneously to said ram cylinder in a direction to move said ram awayfrom said head and to said head cylinders in a direction to move saidhead toward said body. other means for supplyingpower fluid underpressure simultaneously to said ram cylinder in a direction to move saidram toward said head and to said head cylinders in a direction to movesaid head away from said body, and means for removably securing saidhead to said body.

14. In a blowout preventer, a body having a pipe opening therethrough, aram guideway extending laterally from said pipe opening, a ram movablein said guideway to and from a position interrupting said pipe opening,a head removably secured to said body across the outer end of saidguideway and having a pair of ram cylinders formed therein, a ram pistonin each of saidram cylinders connected to said ram, said head alsohaving a pair of head cylinders in said head on either side of said ramcylinders, and a head piston in each of said head cylinders, a rodconnecting each of said head pistons to said body, each of said pistonand cylinder combinations being doubleacting, means for supplying powerfluid under pressure simultaneously to said ram cylinder in a directionto move said ram away from said head and to said head cylinders in adirection to move said head toward said body, other means for supplyingpower fluid under pressure simultaneously to said ram cylinder in adirection to move said ram toward said head and to said head cylindersin a direction to move said head away from said body, said head having arecess in its outer surface 4 between said ram cylinders, a lockingscrew extending from said recess through said head into engagement withsaid ram to lock the same in position interrupting said pipe opening,and means for removably securing said head to said body. 1

15. In a blowout preventer, a body having a pipe opening therethroughand a ram guideway extending laterally from said pipe opening, a rammovable in said guideway to and from a position interrupting said pipeopening, a head removably secured to said body across the outer end ofsaid guideway and having a ram cylinder formed therein, a ram piston insaid ram cylinder connected to said ram, a head cylinder in said head, ahead piston in said head cylinder, a rod connecting said head piston tosaid body, each of said piston and cylinder combinations being doubleacting, and means for selectively supplying power fluid under pressureto each of said cylinders in either direction.

16. In a blowout preventer, a body having a pipe opening therethroughand a ram guideway extending laterally from said pipe opening, a rammovable in said guideway to and from a position interrupting said pipeopening, a head removably secured to said body across the outer end ofsaid guideway and having a ram cylinder formed therein, a ram piston insaid ram cylinder connected to said ram, a headcylinder and pistoncombination interconnecting said head and body, each of said piston andcylin- 14 der combinations being double acting, and means forselectively supplying'power fluid under pressure to said piston andcylinder combinations respectively in either direction.

17. As a subcombination, a head for a blowout preventer comprising abody having a pair of ram cylinders therein and a pair of head cylinderstherein, the axes of all of said cylinders being in substantially thesame plane and said ram cylinders being spaced apart and having a recesstherebetween in the outersurface of the head, and a locking screwdisposed partly in said recess and extending from said recess throughsaid head.

18. In a blowout preventer comprising a body having a pipe openingtherethrough and a ram guideway extending laterally from said pipeopening, a ram movable in said guideway to and from a positioninterrupting said pipe opening, the improvement which comprises a headdetachably secured to said body, piston and cylinder meansinterconnecting said head and ram for moving said rain in its guidewaytoward and away from the head in normal preventer operation, and otherpiston and cylinder means interconnecting said head and body for movingsaid head toward and away from said body when de tached, the pressureresponsive areas of the piston of said first-mentioned piston andcylinder means for moving said ram toward and away from thehead beinggreater than that of the piston of said last-mentioned piston andcylinder means for moving said head toward and away from the body,respectively.

19. A blowout preventer according to claim 18, wherein saidfirst-mentioned piston and cylinder means includes a cylinder formed inthe head, a piston slidable within the cylinder and connected to theram, and passageways in the head connecting with the cylinder forsupplying power fluid to opposite sides of the piston.

20. A blowout preventer according to claim 18, wherein both of saidpiston and cylinder means are connected in series.

Losey June 5,

